Table 1.
Input Parameters for Decision Analysis Model of Methicillin-Sensitive Staphylococcus aureus and Reported Penicillin Allergy
| Description | Baseline Value, % | Range for Sensitivity Analyses, % | Source |
|---|---|---|---|
| Treatment efficacya | |||
| Vancomycin | |||
| MSSA cure | 62.0 | 36.0–90.0 | [7, 8, 16] |
| MSSA recurrence | 18.8 | 0.0–23.2 | [7, 8] |
| MSSA mortality | 19.2 | 10.0–41.0 | [7, 8, 16] |
| Cefazolin | |||
| MSSA cure | 85.0 | 80.0–88.3 | [7, 8, 16] |
| MSSA recurrence | 9.1 | 0.0–10.0 | [7] |
| MSSA mortality | 5.9 | 2.0–6.0 | [7, 16] |
| Alternativeb | |||
| MSSA cure | 86.4 | 36.0–90.0 | [7, 8, 16, 23] |
| MSSA recurrence | 13.2 | 0.0–23.2 | [7, 8, 23] |
| MSSA mortality | 0.4 | 0.0–41.0 | [7, 8, 16, 23] |
| Allergic reactions | |||
| Vanc | |||
| Allergic reaction to vancomycinc | 3.0 | 2.0–6.4 | [39, 40] |
| Allergic reaction to vancomycin considered major | 8.3 | 0.0–10.0 | [40] |
| Hx-Cefaz | |||
| Patients with PCN allergy whose reaction has anaphylactic features | 5.6 | 0.0–11.2 | PEARd |
| Patients without anaphylactic PCN allergy history who react to cefazoline | 2.2f | 0.2–5.6 | [17, 30, 32, 41–44] |
| ST-Cefaz | |||
| Patients not eligible for PCN skin testing | 9.1 | 0.0–11.0 | [20, 21] |
| Patients with a positive PCN skin test | 1.2 | 0.0–10.0 | [20, 21, 24, 25, 45] |
| Patients with a nondiagnostic PCN skin test | 3.2 | 0.0–10.4 | [20, 21, 24, 25, 45] |
| Allergic reaction to cefazolin or nafcillin given a negative skin test to penicilline | 1.6 | 0.1–1.8 | [20, 21, 24, 25, 45] |
| General | |||
| Allergic reaction to cefazolin considered major | 4.7 | 0.0–5.6 | [26, 36] |
| Death from allergic reaction given a major allergic reaction occurs | 0.2 | 0.0–3.8 | [46–49] |
| Adverse drug reactions | |||
| Vancomycin | 5.3 | 0.0–43.0 | [40, 50, 51] |
| Cefazolin | 4.4 | 0.0–7.0 | [40,51,52] |
Abbreviations: Hx-Cefaz, allergy history-guided treatment: if history excludes anaphylactic features, give cefazolin; MSSA, methicillin-sensitive Staphylococcus aureus; PCN, penicillin; PEAR, Partners Enterprise Allergy Repository; ST-Cefaz, complete allergy evaluation with penicillin skin testing, give cefazolin if negative; Vanc, no allergy evaluation, give vancomycin.
a Outcomes defined 12 weeks after initial blood culture.
b Base case outcomes based on 1 study [23]; examined range for outcomes from vancomycin therapy in sensitivity analyses.
c Excludes infusion reactions (eg, “red man syndrome”).
d Partners Enterprise Allergy Repository, accessed November 2013.
e The sum of these reactions were considered potentially iatrogenic allergic reactions.
f Mathematical computation = ∑ (patients who react to cefazolin who are skin test positive + patients who react to cefazolin who are skin test negative) = ∑ [{ proportion of patients skin test positive (0.49)} × {positive predictive value of PCN skin testing (0.4)} × {the cross-reactivity of PCN and cefazolin (0.029)} + {patients who react to cefazolin who are skin test negative (0.016)}] = (0.49 × 0.4 × 0.029) + 0.016 = 0.022 = 2.2%.